InterMune Announces Positive Opinion for Approval of Esbriet(TM) (Pirfenidone) in European Union

BRISBANE, California, December 17, 2010 - — Esbriet to be the first medicine approved for IPF patients in the EU –

InterMune, Inc. (Nasdaq: ITMN) today announced that the Committee for
Medicinal Products for Human Use (CHMP) of the European Medicines Agency
(EMA) has adopted a positive opinion recommending the granting of a marketing
authorization for Esbriet(TM) (pirfenidone) in adults for the treatment of
mild to moderate idiopathic pulmonary fibrosis (IPF), a progressive and fatal
lung disease. The CHMP is the scientific body of the EMA responsible for
reviewing all Marketing Authorization Applications for new medicines. A
summary of the CHMP opinion will be available here:
tinyurl.com/2am4ubc. Please select "E" to access the Esbriet summary
opinion.

The committee's positive opinion will now be forwarded to the European
Commission for ratification, which typically occurs within two to three
months from adoption of the CHMP opinion. Ratification results in approval
for marketing in all 27 member countries of the European Union.

"We are very pleased by the positive opinion adopted by the CHMP,
particularly because it was achieved earlier in the regulatory process than
is typical," said Dan Welch, Chairman, Chief Executive Officer and President
of InterMune. "We are now focusing our efforts on completing our commercial
launch preparations to bring Esbriet to European patients as soon as
possible."

Roland du Bois, M.D., Professor of Respiratory Medicine, National Heart &
Lung Institute, Imperial College, London, and co-chair of the CAPACITY Phase
3 program, said, "IPF is among the most urgent of unmet medical needs in
respiratory medicine, with no approved therapies in the EU and with survival
rates as poor as many forms of cancer. Today's opinion by the CHMP represents
a major milestone in the treatment of IPF and is extremely exciting news for
the more than 100,000 Europeans who suffer from IPF, and for the physicians
who care for them. What all patients have awaited for so long - hope and new
therapy for their disease - will soon be realized."

Esbriet has been granted Orphan Drug designation in Europe, which
provides 10 years of marketing exclusivity; until 2021. In addition,
InterMune has a number of pending patent applications in Europe relating to
Esbriet's formulation and use in IPF patients, particularly related to the
safe usage of the product which, if granted, will provide patent protection
in Europe for at least an additional five years, until 2026, and possibly as
long as an additional nine years, until 2030. One such patent has been
allowed by the European patent office which relates to the effect of food on
the pharmacokinetics and safety of pirfenidone in IPF patients. The company
has an extensive patent position on the Esbriet formulation and uses of
Esbriet in IPF patients, and in the United States the company has already
secured the grant of six new patents that extend the exclusivity period for
the patented formulation and uses of pirfenidone in the U.S. to 2030. If one
or more of the analogous patents are granted in Europe, the company's current
expectation is that Esbriet will enjoy patent protection in both the U.S. and
Europe to at least 2026 or 2030.

The company plans to hold a conference call today at 8:30 a.m. Eastern
time.

Conference Call and Webcast Details

InterMune will host a conference call today at 8:30 a.m. EST to discuss
Esbriet (pirfenidone) and the related Marketing Authorization Application.
Interested investors and others may participate in the conference call by
dialing 888-567-5125 (U.S.) or +1-706-643-9223 (international), conference ID#
33188579. A replay of the webcast and teleconference will be available
approximately three hours after the call.

To access the webcast, please log on to the company's website at
www.intermune.com at least 15 minutes prior to the start of the call
to ensure adequate time for any software downloads that may be required.

The teleconference replay will be available for 10 business days
following the call and can be accessed by dialing 800-642-1687 (U.S.) or
+1-706-645-9291 (international), and entering the conference ID# 33188579. The
webcast will remain available on the company's website until the next
earnings call.

About Esbriet (Pirfenidone)

InterMune submitted a Marketing Authorization Application (MAA) seeking
approval of Esbriet for the treatment of idiopathic pulmonary fibrosis (IPF)
in adults, which was validated by the EMA effective March 24, 2010.

Preclinical and in-vitro evidence has shown that Esbriet has both
anti-fibrotic and anti-inflammatory effects. In February 2009, InterMune
announced the results of the company's two pivotal Phase 3 clinical trials
evaluating Esbriet for the treatment of IPF, known as the CAPACITY trials. In
clinical studies, Esbriet was safe and generally well-tolerated, with the
most frequent side effects reported being photosensitivity rash and
gastrointestinal symptoms. Since 2008, pirfenidone has been marketed in Japan
as Pirespa(R) by Shionogi & Co. Ltd.

About InterMune

InterMune is a biotechnology company focused on the research, development
and commercialization of innovative therapies in pulmonology and hepatology.
InterMune has an R&D portfolio addressing idiopathic pulmonary fibrosis (IPF)
and hepatitis C virus (HCV) infections. The pulmonology portfolio includes
Esbriet(TM) (pirfenidone) for which InterMune has completed a Phase 3 program
in patients with IPF (CAPACITY). The Marketing Authorization Application
(MAA) for Esbriet received a positive CHMP opinion that is now awaiting
ratification by the European Commission. The hepatology portfolio includes
next-generation HCV protease inhibitor and NS5A research programs. For
additional information about InterMune and its R&D pipeline, please visit
www.intermune.com.

Forward-Looking Statements

This news release contains forward-looking statements within the meaning
of section 21E of the Securities Exchange Act of 1934, as amended, that
reflect InterMune's judgment and involve risks and uncertainties as of the
date of this release, including without limitation the statements related to
the anticipated receipt of marketing authorization approval from the European
Commission for the use of pirfenidone for the treatment of IPF and the
expected timing thereof, statements regarding commercial launch preparations
and statements regarding the various anticipated durations of patent
protection and marketing exclusivity. All forward-looking statements and
other information included in this press release are based on information
available to InterMune as of the date hereof, and InterMune assumes no
obligation to update any such forward-looking statements or information.
InterMune's actual results could differ materially from those described in
InterMune's forward-looking statements.

Other factors that could cause or contribute to such differences include,
but are not limited to, (i) whether the European Commission approves the
marketing authorization for pirfenidone for the treatment of IPF and the
actual timing of the decision; (ii) risks related to unexpected regulatory
actions or delays or government regulation generally; (iii) risks related to
the clinical and regulatory process for pirfenidone, including having no
unexpected safety, toxicology, clinical or other issues; (iv) unexpected
clinical trial results, including unexpected new clinical data and unexpected
additional analysis of existing clinical data; (v) government, industry and
general public pricing pressures; (vi) InterMune's ability to obtain or
maintain patent or other proprietary intellectual property protections; (vii)
risks related to building the infrastructure required for commercial launch
in various countries in the European Union, and (viii) those other factors
discussed in detail under the heading "Risk Factors" in InterMune's most
recent annual report on Form 10-K filed with the Securities and Exchange
Commission (SEC) on March 15, 2010 (the "Form 10-K"), and other periodic
reports filed with the SEC. The risks and other factors discussed above
should be considered only in connection with the fully discussed risks and
other factors discussed in detail in the Form 10-K and InterMune's other
periodic reports filed with the SEC, all of which are available via
InterMune's web site at www.intermune.com.

Esbriet is a registered trademark of InterMune, Inc.

Jim Goff of InterMune, Inc., +1-415-466-2228, jgoff at intermune.com